STC rating of double glass sliding doors?

How to use REW, What is a Bass Trap, a diffuser, the speed of sound, etc.

Moderators: Aaronw, sharward

Soundman2020
Site Admin
Posts: 11938
Joined: Thu Aug 21, 2008 10:17 am
Location: Santiago, Chile
Contact:

Re: STC rating of double glass sliding doors?

Post by Soundman2020 »

wouldn't part of the problem be the STC rating of each individual door, not the rating of them combined?
Not really. An MSM wall is a tuned system: change one thing and you change the entire tuning. The idea is to adjust the parameters (mass and air gap, mainly) to get the resonant frequency down to less than half of the lowest frequency that you want to isolate. If you have less mass on wall, then you need a greater distance between them to get the same resonant frequency.
wouldn't the doors become your weakest link?
Doors (and windows) are usually the weakest link, regardless of the type that you use. But the issue isn't so much mass as it is sealing. You can have a pair of hugely massive doors with a large air gap between them, but if they are not extremely well sealed then you wasted a lot of money!
ie you only need to build your walls to the same quality as your doors.
The normal approach is to start the other way around: design your walls to get the level of isolation that you need (based on your design parameters), then figure out how to get your doors and windows up to the same level of isolation as the walls. That might involve more mass in the door/window, or larger air gaps, or both, but it absolutely certainly will involved several sets of very tight seals.
If you built a wall with say, 2 layers of 16mm plasterboard and some green glue, much of this expense would be wasted as soon as you added sliding doors with an STC of 33 or similar?
Not necessarily! You would choose your doors mass (ie, glass thickness, type, density) with the correct amount of mass for the application, and also choose the air gap of the right size for that mass. An pair of back-to-back sliding doors rated at STC 33 each might well do the trick, depending on the design goals. They don't act individually in an MSM wall, but rather act together, as part of the entire tuned system.
I can't find anywhere that can tell me the stc of 16mm plasterboard, GG, 16mm plasterboard, alone.
Single leaf? Not very good. Single leaf is limited by mass law, so you are basically talking about the mass of 32mm of drywall. That would maybe get you in the high 20's or so, depending on how well it is sealed, how it is mounted, etc.

Just checking here: You are aware that STC is a lousy method for judging the isolation of a wall for studio use? You should never use STC rating for studio design.


- Stuart -
ToneAlive
Posts: 50
Joined: Fri Mar 09, 2012 3:08 pm
Location: Detroit Area Michigan, USA

Re: STC rating of double glass sliding doors?

Post by ToneAlive »

Does anyone know where I can get sliding glass doors that only have the door side? ..which then slide into the wall. The reason I need this instead of the traditional sliding glass door with two sections of glass is because the opening that I want them for is only about 4 feet. And since I only need one side, it seems like I could get them cheaper. Has anyone heard of such a thing?

Also, what are the methods and products for adding seals to a sliding glass door if is not isolating enough based on a sealing problem?
Soundman2020
Site Admin
Posts: 11938
Joined: Thu Aug 21, 2008 10:17 am
Location: Santiago, Chile
Contact:

Re: STC rating of double glass sliding doors?

Post by Soundman2020 »

It sounds like you are describing a pocket door, where there is only one panel that slides into the wall, instead of sliding past the other one?

- Stuart -
ToneAlive
Posts: 50
Joined: Fri Mar 09, 2012 3:08 pm
Location: Detroit Area Michigan, USA

Re: STC rating of double glass sliding doors?

Post by ToneAlive »

Soundman2020 wrote:It sounds like you are describing a pocket door, where there is only one panel that slides into the wall, instead of sliding past the other one?

- Stuart -
Yeah, exactly .. Except I've never seen one where the the door is glass!
Post Reply